Regime change would be putting it lightly. The Bills ousted head coach Chan Gailey in favor of Doug Marrone, who in turn brought in Nathaniel Hackett (his right-hand man at Syracuse) and Mike Pettine (formerly of the New York Jets) as his offensive and defensive coordinators, respectively.

The changes extended into the front office as well. Analytics-loving strategist Russ Brandon was promoted to team president, and general manager Buddy Nix was put on alert with the news that Doug Whaley will be his eventual successor.

All of this presented a clear message to the Bills' passionate fan base that mediocrity will not be tolerated moving forward.

Biggest free agents

» LG Andy Levitre: One of the rare bright spots on the Bills' offensive line last season. His durability (64 consecutive starts) and pass-blocking ability at guard make him one of the top offensive linemen on the market.

What they need

The defense obviously struggled last season, allowing 27.2 points per game. This forced quarterback Ryan Fitzpatrick into come-from-behind situations that exposed his below-average arm strength and led the Bills away from their biggest strength: getting the ball to playmaker C.J. Spiller.

Cornerback Stephon Gilmore, the Bills' first-round pick in 2012, came along late in the season -- as did highly paid free-agent defensive end Mario Williams -- offering a glimmer of hope. But the Bills must retain Jairus Byrd to continue this defensive progress. Bringing in Pettine (whose defense ranked in the top 10 all three seasons he was in charge in New York) should also help.

In terms of draft and free agent acquisitions, the Bills desperately need help in their linebacker and receiving corps, as well as on their offensive line. Notre Dame linebacker Manti Te'o is a name that pops up often in discussions involving the No. 8 pick. Whether that's phantom talk or not remains to be seen. Inside linebackers, no matter how highly touted, rarely are picked in the first round these days.

Another popular first-round candidate is quarterback Ryan Nassib, whom Marrone and Hackett mentored at Syracuse. Acquiring a franchise quarterback is a well-known priority for Nix, but the show Nassib put on at Senior Bowl was far from encouraging. Waiting until the second or third round and taking a gamble on a less-heralded quarterback, a la the Seattle Seahawks and Russell Wilson, might be the better play here.

Offseason crystal ball

The Bills' decision to apply the franchise tag to safety Jairus Byrd is huge since he's the team's defensive backbone. Losing the second team All-Pro, who is still in his prime at 26, would be quite a blow for Buffalo's turnover-starved defense -- he accounted for five interceptions and four forced fumbles. Expect the Bills to competitively pursue Levitre -- whose loss could be softened by retaining promising backup Chad Rhinehart, who is also a free agent.

Don't expect many big splashes from the Bills, but they do have $16.7 million in cap room to play with. A loaded free agent wide receiver crop could work in their favor, value-wise. They could certainly use another pass catcher to take attention away from 1,000-yard threat Stevie Johnson.

Even if the Bills cut Fitzpatrick, a $10 million move, the resulting cap hit would be too substantial to make it a feasible move. It's more likely they'll draft their quarterback of the future and leave Fitzpatrick in the mix for competition purposes.